Surface conditioning attachment

ABSTRACT

A surface cutting attachment for a powered floor abrading or polishing machine, said attachment having a plurality of frusto-conical blades releasable secured in a support having a complimentary frusto-conical socket. Upon the cutting edge becoming worn the frusto-conical blade can be rotated to present a previously unused part of the annular cutting edge. The blades are mounted on a rotatable plate in equally spaced circumferential intervals and a plurality of plates are rotatably mounted at equally spaced circumferential intervals on a power drive disc.

BACKGROUND OF THE INVENTION

The present invention is related to improved equipment for removing adherents from surfaces and simultaneously developing a relatively smooth surface. In particular, the present invention is related to an improvement in the ability to remove adherents such as paint and the like from concrete surfaces.

The art of surface refinement for concrete is now well practiced. In general, concrete, either newly poured or existing, is ground to a smooth surface to improve the appearance. The grinding is typically accomplished by a grinding machine comprising a multiplicity of moving abrasive tools. The abrasive tools move across the surface and remove a sufficient amount of the concrete to create a smooth surface. Abrasive are well known and typically include bits of diamond, or similar hard material, in a binder. The ratio of binder to abrasive and abrasive particle size defines the aggressiveness of the abrasive. It is common to abrade the surface with decreasingly aggressive abrasives such that the final treatment polishes the surface to the final smoothness desired.

It is not uncommon for surfaces to have a coating thereon. Paints are frequently used, as are adhesives and glues for tiles, carpet and the like. Removing coatings from a surface can be very difficult. Abrasives are very inefficient at removing soft materials since they tend to clog. Therefore, prior to treating the surface with an abrasive, the surface coating or treatment must be removed. There are many ways of removing the surface treatment, none of which are satisfactory. Solvents can be used but this technique is not desirable for a myriad of reasons, all of which are self-explanatory. Projectile approaches, such as sand blasting, pressure washing and the like can be used but they are unacceptable in closed areas or places where the high volume of dust and/or moisture is unacceptable. Furthermore, the equipment utilized for such operations is totally different from that used to polish a floor thereby requiring equipment to be brought into the area twice. This is highly undesirable in a business that is constantly confronted with demands for lowered cost.

It would be highly desirable to have a system for removing adherents from a surface which is compatible with a grinding system thereby eliminating the necessity of multiple trips to the same job site. It would also be highly desirable to have a system which can remove adherents from a surface without requiring a projectile which scatters removed material, and the projectile, over large areas. These demands have not been adequately met in the past.

SUMMARY OF THE INVENTION

An improved surface finishing tool is provided with a plurality of circumferentially spaced frusto-conical cutters or blades mounted on the underside of an annular plate which is rotatable about a vertical axis. Each blade is secured to an igloo or dome shaped support presenting a frusto-conical socket for receiving a frusto-conical cutter which is held in place by a coaxially positioned cap screw threaded into a threaded opening in the igloo shaped support. An exposed portion of a large diameter edge of the blade performs an efficient scraping or cutting action for removing surface coatings or adhesives, which are more difficult to remove when using rubbing type abrasion or polishing tools. Upon occurrence of wear the blade can be rotated to a new position, thus providing an efficient floor resurfacing tool with excellent service life.

DESCRIPTION OF DRAWINGS

The invention is illustrated in the accompanying drawings, in which:

FIG. 1 is a perspective view of a rotary plate to which six cutter assemblies are attached;

FIG. 2 is an exploded view showing a frusto-conical cutter and its mounting fastener;

FIG. 3 is a bottom view showing three rotary plate rotatably mounted on a driven disc;

FIG. 4 is a bottom perspective view showing a plate being secured to its shaft;

FIG. 5 is a section taken on line 5-5 in FIG. 3;

FIG. 6 is a section taken on line 6-6 in FIG. 5, and

FIG. 7 is an enlarged partial section view of the blade showing its tapered cutting edge.

DETAILED DESCRIPTION OF THE INVENTION

The invention is described with particular reference to the accompanying drawings forming a part of the present specification. The instant invention is directed to an improved surface treatment apparatus and method wherein surface adherents are removed efficiently and thoroughly by use of cutter assemblies having a replaceable carbon steel frusto-conical cutter or blade 20 with an annular beveled cutting edge 24. By contacting the floor surface with the beveled cutting edge 24, the problems associated with material buildup on prior art abraders are eliminated.

A power rotated horizontal plate 10 for a floor conditioning machine, illustrated in a bottom perspective view in FIG. 1, has a central mounting void 12, with primary lobes, 14, and secondary lobes, 16, which facilitate connection of the plate 10 to a power driven shaft, not shown, by a connector 19 as shown in FIGS. 3 and 4. As shown in FIG. 3, three plates 10 are secured to three shafts 46, 47, 48 rotatably mounted on a horizontal power driven disc 17 of a floor polishing machine and are rotated about equally spaced vertical axes 52, 53, 54 defining a circle concentric to the axis 43 of the disc 17. Rigidly secured to each plate 10 near its circumference and extending downwardly there from are igloo shaped supports 18, each of which have a frusto-conical socket 31 adapted to accept a frusta-conical blade 20. The blade 20 is mounted such that its parallel faces 36, 37 are substantially perpendicular to the plate and the surface being abraded. Each of the blades 20 is attached to its igloo shaped support 18 by a threaded fastener or screw 22, which is in threaded engagement with a threaded opening 26 of the annulus 20. The screw 22 includes a tapered end portion 27 which mates with the tapered shoulder 23 of the screw 22 when it is installed. The plate 10 is driven about its axis in the direction of the arrow 29, shown in FIG. 1, thereby presenting a sharp edge 24 which removes material adhering to the floor.

A particular advantage of the instant invention is the ability to loosen and rotate the blade 20 to present a new section of the cutting edge 24, thereby greatly extending the life span of the blade 20.

Each igloo shaped support 18 is welded to the plate 10 at equal intervals forming a circumferential ring of blades 20. Each igloo shaped support 18 has a frusto-conical shaped socket 31 with which the complimentary shaped frusto-conical shaped surface 32 of the blade 20 engages in a wedging fit upon tightening of the screw fastener 22. The wedging fit of the frusto-conical surfaces of the socket and the blade 20 and the wedging fit of the tapered head of the screw 22 nonrotatably secure the blade 20 to its support 18. The front face 36 of the blade 20 and the rear face 37 of the blade 20 are substantially parallel, with the radially outer edge of the front face 36 tapering axially outwardly thereby forming a tapered circumferential cutting lip 38 with the sharp tapered cutting edge 24.

As illustrated, the igloo shaped support 18 is notched presenting a vertical wall 41, in general alignment with the face 36 of the blade 20, and a horizontal shoulder 42 positioned below the lower edge of the socket 31. During a floor surface operation the disc 17 is driven clockwise about its vertical axis 43 indicated by an arrow 44 in FIG. 3 and the plates 10 are also rotated clockwise about their axes as viewed in FIG. 3. FIG. 4 shows a plate 10 being secured to its drive shaft 46. The other two drive shafts 47, 48 await installation of their respective plates 10. Three downward extending flaps 51, positioned in equal circumferentially spaced relation to one another and in interstice relation to the power driven plates 10, are provided to sweep away material removed from the floor by the blades 20.

Prior art floor abrading devices present a flat abrasion face which is parallel to the surface. A particular problem is the accumulation of material in the roughened face of the abrasive. As abraded material, surface dust and dislodged abrasive particles are created they tend to lodge in the surface of the abrasive thereby decreasing the effectiveness. With the present invention a relatively sharp cutting edge is presented, instead of a flat face thereby eliminating the accumulation of particles on the surface working tool. As a result the amount of time required to clean a large area is decreased due to the self cleaning feature of the blade 20. As the cutting edge wears, the blade can be rotated very easily to prevent a new edge. In order to renovate the usual power driven floor abrader, the abrasive element must be frequently replaced at considerable operating expense. 

1. A surface cutting attachment for a powered floor conditioning machine comprising: a horizontally disposed disc adapted for connection to said machine for driven rotation about a first vertical axis, three horizontal disposed annular plates rotatably mounted on the underside of said disc for rotation in a predetermined direction about equally spaced vertical axes defining a circle concentric with said first vertical axis, and at least three cutter assemblies mounted near the circumference of and extending downwardly from each of said plates, said cutter assemblies being equally spaced circumferentially to define a circle concentric with said plate upon which they are mounted and each including an igloo shaped support rigidly secured to the underside of its associated plate, said support having a notch with a vertical wall, said vertical wall having a facing frusto-conical socket formed therein facing in said predetermined direction, and a frusto-conical blade having a frusto-conical surface in wedging engagement with said socket, said frusto-conical blade presenting a radially outer leading cutting edge having a portion extending downwardly beyond said igloo shaped support, said cutting edge being adapted to cuttingly engage a floor surface when said plate is rotated in said predetermined direction of said leading edge.
 2. The attachment of claim 1 wherein said leading edge is tapered.
 3. The attachment of claim 1 wherein said blade is releasably secured to said support by a releasable fastener and wherein upon release of said releasable fastener, said blade is rotatably positionable to present a different portion of said cutting edge in cutting relation to said floor.
 4. The attachment of claim 1 wherein said attachment includes six cutting assemblies.
 5. The attachment of claim 1 wherein said blade includes an annular opening concentric with the axis of said blade and said igloo shaped support includes a threaded annular opening concentric with said socket and further comprising a threaded fastener extending through said annular opening and in threaded engagement with said threaded annular opening.
 6. The attachment of claim 5 wherein said threaded opening includes an unthreaded tapered end portion in said socket and wherein said screw includes a tapered shoulder in engagement with said tapered end portion.
 7. The attachment of claim 1 wherein a downward extending flap is secured to a part of said disc between said plates, said flap being operative to sweep abraded material from the floor during rotation of said disc.
 8. The attachment of claim 7 wherein a flap is secured to said disc between each circumferentially adjacent pair of said plates. 